1. Field of the Invention
The invention relates to floating melt zone processing of semiconductor rods and somewhat more particularly to an apparatus for the floating melt zone processing of semiconductor rods which include an axially fixed induction heating coil.
2. Prior Art
Apparatuses are known for the floating melt zone processing of semiconductor rods wherein the rod to be processed is positioned vertically between a pair of opposing rod support means within a housing having an induction heating coil positioned to annularly encompass a zone on the rod and which upon energization produces a melt zone on the rod, along with a high frequency generator coupled to the coil via a high-frequency cable. The rod support means and the heating coil are, in these type of apparatuses, movable relative to one another.
For example, German Pat. No. 1,138,375 or U.S. Pat. No. 3,160,478 describe devices of this type. The devices there described are used for changing a rod cross-section as the rod is undergoing a floating melt zone process and to that end, the rod may be vertically mounted between the rod support means which are movable in relation to one another and to the heating coil, which is in a fixed position.
A semiconductor rod processed in such apparatuses can only be removed from the processing chamber via an access opening or the like therein which must be at least twice as high as the overall length of the rod. This type of processing device is shown in German Pat. No. 1,151,669 and in U.S. Pat. No. 3,189,415. However, such devices require very high access openings, particularly when relatively long rods (for example, having a length in excess of 1 meter) are to be melt zone processed and such high access opening containing devices are economically and technically difficult to produce.